How to handle Solutions, Projects and their contents in a VisualStudio extension - wpf

Question

In short:
I'm new to VisualStudio Extensibility and my goal is to create an extension with a ToolWindow (which already works) showing different views for each context of a VisualStudio solution, i. e. a view for the solution, a view for a project etc.. The window should be opened by clicking on a context menu entry in the context menus of the Solution Explorer, Class View, Object Browser and (ideally) any other window showing contents like projects, namespaces, classes etc..
After searching I found a lot of information, but for some points I couldn't find very helpful information. How do I ...
... create a context menu item for the VisualStudio views?
... get the currently open solution as an instance in code?
... get the projects of the solution and their contens as instances in code?
... add/remove items to/from a solution/project/class/... in code?
... react to selection changes in the Solution Explorer?
What I've done, so far:
I read the docs for Starting to Develop Visual Studio Extensions and downloaded the VSSDK-Extensibility-Samples. Especially the WPF_Toolwindow example was interesting for my purposes, so I built and ran it, which was successful, so far. Another interesting sample would have been the WPFDesigner_XML, but it always throws a NullReferenceException, so I decided to stick with the former ToolWindow, which is completely fine, for now.
Furtermore, I tried to understand the example by having a close look at each file in the project, running it in the debugger and analyzing what happened. I'm confident I understood it, but am also open for corrections of my possibly misguided thoughts following.
Now, I have created a new project, based on the WPF_Toolwindow sample, renamed and adapted to my needs (basically, I created new GUIDs, renamed the namespaces and removed things I won't use). This extension still works in the debugger. I even uninstalled everything from the experimental instance and debugged the extension from scratch.
What I try to achieve:
Have the ToolWindow load a specific view/viewmodel, when the selection changes in the Solution Explorer (or any other VisualStudio view). Alternatively, there should be a context menu item for every node's context menu in the Solution Explorer tree (or any other VisualStudio view).
Get the currently open solution, the containing projects and basically everything from the Solution Explorer's content as instances processable in my viewmodel. I need to properly add/remove
classes/structs/enums to/from
a folder in a project
a namespace
properties/fields to/from a class/struct
Generate code based on information of the solution and add the file properly to a project.
Does anyone know of examples for something like this or can anyone give me some hints, where I can find further information? Any help would be appreciated. Thanks in advance.

Answer 1

(1) The items already have a context menu and I want to add a new command to this menu.
if you want to add a sub menu to the context menu, the following link provide a complete sample
https://github.com/visualstudioextensibility/VSX-Samples/tree/master/CommandSubmenu
(3) Yes, basically adding a file to a project without manually manipulating the project file would be nice.
You can add the file to project via Project.ProjectItems.AddFromFile, and the following provide a sample for your reference.
https://www.mztools.com/Articles/2014/MZ2014009.aspx
Update:
I select a project and a similar event is fired. Are there such events I can subscribe to?
You could use IVsMonitorSelection to implement. here is the code which retrieve related project path for your reference.
IntPtr hierarchyPointer, selectionContainerPointer;
Object selectedObject = null;
IVsMultiItemSelect multiItemSelect;
uint projectItemId;
IVsMonitorSelection monitorSelection =
(IVsMonitorSelection)Package.GetGlobalService(
typeof(SVsShellMonitorSelection));
monitorSelection.GetCurrentSelection(out hierarchyPointer,
out projectItemId,
out multiItemSelect,
out selectionContainerPointer);
IVsHierarchy selectedHierarchy = Marshal.GetTypedObjectForIUnknown(
hierarchyPointer,
typeof(IVsHierarchy)) as IVsHierarchy;
if (selectedHierarchy != null)
{
ErrorHandler.ThrowOnFailure(selectedHierarchy.GetProperty(
projectItemId,
(int)__VSHPROPID.VSHPROPID_ExtObject,
out selectedObject));
}
Project selectedProject = selectedObject as Project;
string projectPath = selectedProject.FullName;
For more information about the usage, please refer to:
https://www.mztools.com/articles/2007/mz2007024.aspx